PHP Getting all file names in dirctory for page switching - php

Question

Right now I have all my pages under a switch case for when a visitor uses whatever.php?p=pagename
Here is how it is currently
switch($page)
{
case 'about':
include('pages/about.php');
break;
case 'contact':
include('pages/contact.php');
break;
case 'edb':
include('pages/edb.php');
break;
case 'eluna':
include('pages/eluna.php');
break;
case 'mercsys':
include('pages/mercsys.php');
break;
case 'pastebin':
include('pages/pastebin.php');
break;
case 'projects':
include('pages/projects.php');
break;
case 'sites':
include('pages/sites.php');
break;
case 'soon':
include('pages/soon.php');
break;
case 'sqlgen':
include('pages/sqlgen.php');
break;
case 'wcms':
include('pages/wcms.php');
break;
case 'add':
include('pages/add.php');
break;
case 'edit':
include('pages/edit.php');
break;
case 'delete':
include('pages/delete.php');
break;
case 'moveAnnouncement':
include('pages/moveAnnouncement.php');
break;
default:
include('pages/404.php');
}
My question is, How can I shorten this down to a foreach loop and use the page names for each .php in the pages/ directory without having to add each individual one or any future pages?

Answer 1

upd: like #svrnm adviced, you can do some security checks if you not did it before:
$filename = realpath('pages/' . $page . '.php');
if($filename && file_exists($filename)) {
include($filename);
}
or/and you can build files whitelist first:
$whitelisted = glob("*.php");
if(in_array($page . '.php', $whitelisted) && file_exists($filename)) {
include($filename);
}